Maybe you read something about this on your phone, or saw a story on television. This week has been Screen-Free Week. Kids and parents around the world made pledges to stop using TVs, tablets, computers or video games - for a while.

The notion is to get kids to spend more time being physically active, playing outside or reading. Kids under 18 spend an average of seven hours and 38 minutes on media devices each day - which concerns pediatrician Michael Rich.

DR. MICHAEL RICH: Because kids now spend more time with media than they spend with anything except sleep, it seemed necessary to have someone who specialized in really understanding the science of how we are affected and changed by the media we use.

INSKEEP: Dr. Rich says that someone is him. He calls himself a mediatrician. He's the founder of the Center on Media and Child Health at Boston Children's Hospital. And he contends greater screen time leads to greater anxiety, more aggressive behavior. He also sees a physical effect.

RICH: There is a huge obesity problem in the U.S., and it upticked in exact parallel with our uptick in use of screen media.

INSKEEP: All that said, he's not sure that an outright ban on screens is a solution.

RICH: When you create the absolutes of no TV at all, you create the forbidden fruit.

INSKEEP: So instead, he recommends what he calls a digital Sabbath.

RICH: Twenty-four hours once a week where everything is off, just to reset and just get back in touch with each other and with life.

INSKEEP: Yeah. No problem. You can just set an alarm for yourself on your phone that can go off when the 24 hours is up. Rich says some screen media can be educational. He wouldn't mind kids watching a documentary on whales, for example.

RICH: You can learn different and probably more things from actually seeing sperm whales migrating than you do from reading it in a book.

INSKEEP: Although you could just listen to them on the radio.

(SOUNDBITE OF WHALE)

INSKEEP: What the whale is saying is, that's the business news on MORNING EDITION, from NPR News. Our theme music was composed by B.J. Liederman and arranged by Jim Pugh.